Mobile devices for wireless networks scan for signals and channels in order to synchronize with the wireless network. Where the wireless network is a Long-Term Evolution (“LTE”) network, an evolved Node B (“eNB”) is a base station that broadcasts primary synchronization signals (“PSS”) and secondary synchronization signals (“SSS”) as cell-identification signals in each system frame. The eNB also periodically transmits other general signals that are not specific to a mobile device, such as common reference signals, and network configuration data, such as a master information block and system information blocks. The eNB consumes power to transmit the general signals and network configuration data even when there are no mobile devices with an active connection. In some cases, the eNB is configured for a reduced activity state or dormant state. At least while mobile devices are connected to the eNB, the eNB must provide a notification to the mobile devices when the network configuration data have changed.
The eNB must also periodically transmit a cell-identification signal so that other mobile devices can detect the eNB, for example, for a handover between eNBs or when a user turns on his mobile device. Cell-identification signals such as the PSS and SSS are susceptible to “pilot pollution” and “pilot collision” when cells are very close to each other. For example, a wireless network operator can place several small cells in an area where he wishes to offload data from a macro cell. In this case, the cell-identification signals from each small cell can cause interference with other small cells which are in close proximity.